102 



THE ART OF MAKING MICROSCOPE SLIDES 



Casting block 



l)ox will be aliout J4 that of the sheet 

 taken, but a little experience will soon 

 show what size sheet to take for the box 

 required. The sheet is laid on a fiat surface 

 and the long sides folded inwards (Fig. 39) 

 until they very nearly meet in the middle. 

 These folds are well creased with the 

 thumbnail. The sheet of paper is then 

 flattened again and the other two edges 

 (Fig. 40) folded in the same manner. It is 

 necessary, however, that this fold be much 

 larger than the first fold made. These folds 

 are also well creased with the thumbnail. 

 The folded sheet is then laid out (Fig. 41) 



Fig. 45 as there are boxes to be made. 

 Center the sheet between the finger and 

 the thumb (Fig. 46) and then fold up the 

 sides (Fig. 47) creasing the paper where it 

 is in contact with the edges of the block. 

 Push up the end with the forefinger (Fig. 

 48) creasing both the paper in contact 

 with the block and the flaps. Fold the 

 flaps to the center (Fig. 49), being careful 

 to get them straight and creasing them up 

 the sides. Fold down the projecting flap 

 (Fig. 50) and crease it firmly. Repeat these 

 operations with the other side of the block 

 and then slide the box off the end of the 



Length of box + twice height of box + twice length of flaps 



XI 



o 



o 

 Xi 



i 



Fig. 45. Dimensions of sheet for folding a paper box. 



and the corners folded in the manner 

 shown. Since these end folds are larger 

 than the side folds there will be an over- 

 hanging flap of paper at the top. After all 

 four corners have been folded in, this 

 overhanging flap (Fig. 42) is folded back 

 over the triangular folded corner sections 

 and this crease particularly firmly pressed 

 with the thumbnail. When this has been 

 done at each end, the box is finished and 

 may be opened out as shown in Fig. 43. It 

 will be found that the corners are not 

 scjuare but may be squared by pressing 

 with the thumb and forefinger in the 

 manner shown. The finished box is shown 

 in Fig. 44. 



There is a very convenient method of 

 folding small boxes wliich requires a series 

 of wooden blocks of cross-section ecjual to 

 that of tlie boxes recjuired. Take such a 

 block (Figs. 46-51) and as many sheets of 

 bond paper of the dimensions shown in 



block (Fig. 51). It is well to have a series 

 of these blocks made both in square and 

 rectangular shapes. An additional advan- 

 tage of this type of box is that one can put 

 the data about the block on the flaps. 

 Boxes cannot be made by this method 

 much larger than 1" X H". 



Some people prefer to cast a series of 

 rectangular boxes from plaster of Paris. 

 This can be done by any competent crafts- 

 man, but will not be described at this 

 point. 



After the box has been prepared we 

 come to the actual process of embedding 

 which is shown in detail in Figs. 52-55. 

 Before starting it is necessary to make sure 

 that the following items are available: (1) 

 a dish of water of sufficient size that the 

 finished block may be immersed in it (in 

 the illustration an ordinary laboratory 

 fingerl)owl is in use); (2) some form of 

 heat, an alcohol lamp being just as effec- 



